Can I subscribe to Meteor Session for reactive template render updates?

Question

Is there a way to subscribe to the Meteor Session object so that a reactive template view automatically renders when data is .set on the Session object? Specifically the ke

Answer 1

Yes you can subscribe to Session values.

Take a look a the docs for autosubscribe:

http://docs.meteor.com/#meteor_autosubscribe

// Subscribe to the chat messages in the current room. Automatically
// update the subscription whenever the current room changes.
Meteor.autosubscribe(function () {
Meteor.subscribe("chat", {room: Session.get("current-room");});
});

This code block shows one way to use this. Basically any time the value of "current-room" is changed Meteor will update the views.

EDIT

I misunderstood the initial question and decided I need to redeem myself somewhat. I just did some tests and as far as I can tell you can currently only subscribe to collection.find() and session.get() calls. So you can't subscribe to the whole session object or even to the keys object.

However, you can set a Session value to an object this may not be the most elegant solution but this worked for me on keeping track of the keys object with some hackery to keep from getting a circular object error.

var mySession = {
  set: function(key, val){
    var keys = Session.keys,
        map = {};
   Session.set(key, val);

    for (var prop in keys) {
      if(!(prop === "keys")){
        map[prop] = keys[prop];
      }
    }
    Session.set('keys', map);
  }
};

This gives you something that looks a lot like original functionality and can help you keep track and update templates as you add or change Session values.

Here's my template helper (borrowed from previous answer):

Template.hello.keys = function() {
  map = [];
  keys = Session.get('keys');
  for (var prop in keys) {
    map.push({key:prop, value:keys[prop]});
  }
  return map
};

And here's the actual template:

This way you can just call mySession.set("thing", "another thing") and it will update on screen. I am new to Javascript so someone please let me know if I'm missing something obvious here, or let me know if there is a more elegant way of doing this.